Catalytic hydrocarbon conversion process and apparatus therefor



v. vooRHEEs 2,433,798

CATALYTIC HYDROGARBON COVERSION PROCESS AND .APPARATUS THEREFOR Dec. 3o,1941 Filed July 51, 1940 2 Sheets-Sheet l NRNAN N. SSNSNK SRS Dec. 30,1947, v. voRHEEs 2,433,798

CATALYTIC HYDROCARBON CONVERSION PROCESS AND APPARATUS THEREFOR FiledJuly s1, 1940 2 sheets-sheet 2 Ewa/JL llzderaeer r/ees a al JW,

i reaction products.

Patented Dec. 30, 1947 UNITED sTATEs PATENT or-FlcE CATALYTICHYDROCARBON CONVERSION PROCESS AND APPARATUS THEREFOR VanderveerVoorhees, Hammond. Ind., assignor to Standard Oil Company, Chicago,Ill., a corporation of Indiana Application July 31, 1940, Serial No.348,709

4 Claims. (Cl. 196-52) 'I'his invention relates to methods and appara.-tus for catalytic processing and more particularly to such methods andapparatus employing powdered catalysts. It also relates generally tomethods and apparatus for contacting vapors with a suspended powderedsolid.

In a variety of catalytic processes, it has been foundladvantageous toutilize solid catalysts in powdered form. These catalysts are suspendedin the vapors to be processed or converted and the powdered catalyst isthenv separated from the In many instances the catalyst requiresrevivilcation to burn of! carbonaceous deposits or to remove otherimpurities and such reviviiication can be accomplished by suspendinglthe powdered catalyst in a revivifying gas followed by separation ofthe catalyst and return of it to the reaction zone.

This type ofv process is of particular utility in the art of convertingpetroleum or other hydrocarbons and still more particularly in suchprocesses vas catalytic cracking, catalytic reforming,

catalytic dehydrogenation and aromatization, catalytic isomerization andother catalyzed conversion reactions. It is likewise applicable tooxidation and other reactions involving non-hydrocarbon as Well ashydrocarbon vapors.

In'the various processes which are susceptible to influence by powderedcatalysts, it is often highly advantageous and sometimes imperative toutilize very high ratios of the amount of catalyst to the amount ofreacting vapors. Thus ratios of 2 to 1, 3 to l or even 5 to 1 on aweight basis are not at all unusual and ratios as high as 20 to 1 aresometimes preferred in such processes as catalytic cracking of gas oiland particularly catalytic reforming of naphthas. These high ratios ofcatalyst to reactants necessarily entail serious problems both inhandling such concentrated suspensions and in the expense involved inthe use of these very large amounts of catalyst.

Accordingly itl has been found desirable to.

carry out such reactions in enlarged upfiow reactors in which thecatalyst and reactant vapors are both supplied near the bottom of thereactor and in which the vapor velocity and catalyst particle size areso proportioned that the catalyst particles do not pass upward at thesame rate as the vapor but rather slip downward with reference to thevapor stream although moving, on

the average, slowly upward with reference to the reactor. The result isthat a high catalyst to reactant ratio is built up within the reactorbut a relatively low ratio `of catalyst to reactant is chargedto theapparatus. Ultimately the cat- 2 alyst particles pass out of the reactorat the top and are then separated from the vapors, revivied andreturned.

The revivication can be accomplished by the use of a simple type ofreaction vessel, suspending the catalyst in air, a mixture of flue gasand air or other oxidizing gas, in order to burn off from the catalystparticles the carbonaceous deposits, the removal of which is normallythe main obj ective of the reviviiication reaction.

While these upilow reactors are markedly advantageous, those known tothe art prior to my invention have been subject to certain seriousdisadvantages,

One of the most serious of these disadvantages is that when built in thesizes required for commercial processing and particularly in the verylarge sizes necessary to handle the volumes involved in petroleumconversion units such as catalytic cracking and catalytic reformingunits, a type of channeling tends to occur in the reactor with theresult that the bulk of the vapors tend to pass upward in a column or"chimney within the reactor and the catalyst tends to pass downward inone or more similar columns with the result that the contacting of thecatalyst with the vapors is very incomplete and highly nonuniform. Othertypes of uncontrolled turbulence likewise occur with these same resultsof incomplete and non-uniform contacting of vapors and catalyst.

Another disadvantage commonly encountered in this type of system is thatthe powdered catalyst tends to agglomerate into small, hard masses orbeads probably as a result ci the revlvification reaction, and theagglomerated particles with their high sedimentation rates are nothandled eicienty and eiectively by the upflow reactors.

The objects of my invention include the elimination of the diillcultiesabove outlined and other difliculties heretofore encountered inconnection with the use of powderedcatalyst systems and other systems inwhich vapors are contacted with.

trolled contacting in systems employing high ra- 4 4 tios of catalyst tovapors.

A further object of'my invention is to eliminate the problems incidentto the formation of larger agglomerates or beads in powdered catalystsystems and to render the material of which these agglomerates or beadsare composed elhciently and continuously utilizable in the process.

It is also an object of my invention to provide methods and apparatusfor reactions of the powdered catalyst type which will make possible theuse of concentrated suspensions of the powdered catalyst in the vaporscontacted therewith and which will make possib`e the eicient use ofpowdered catalysts having a relatively wide range of particle sizes.

Other and more detailed objects, advantages and uses of my. inventionwill become apparent as the description thereof proceeds.

Briefly, I utilize an upiiow reactor, which may be referred t as aretarded settling reactor, in which there are alternate zones of highand low vapor velocity with the result that in the zones of low vaporvelocity sedimentation occurs to a large extent with consequent buildingup of high catalyst to vapor ratios while in the zones of high vaporvelocity the catalyst is redistributed in the vapors and any channelingwhich may occur in any given low vapor velocity zone cannot extend tothe next such zone so that the vapors and catalyst passing through theapparatus are uniformly contacted with each other. The high velocityzones also act as a seal or lock to prevent catalyst passing downwardthrough the reactor counter to the vapor stream.

In one form `of my invention I also provide equipment whereby the largercatalyst particles, either those present in the catalyst originallysupplied to the process or those formed by agglomeration in the courseof the use of the catalyst, or both, are settled out at the bottom ofthe reactor and are continuously reground and resuspended in the vaporsso that they are always eiiiciently utilized and never build up inundesirable quantities.

My invention will now be described with particular reference to theaccompanying drawings which showcertain embodiments of my invention inhighly diagrammatic form and in which:

Figure 1 is a simplied diagrammatic elevation of one embodiment of myinvention applied both to a powdered catalyst reaction system and to anassociated powdered catalyst revivication system;

Figure2 is an elevation, partly in section, illustrating one way inwhich the grids shown in Figurel can be made adjustable;

Figure 3 is an elevation, partly in section, showing an alternative typeof reactor preferably used in powdered catalyst conversion reactions butalso adapted to regeneration reactions;

Figure 4 is a sectional detail elevation illustrating 9, still furtheralternative form of reactor; andv Figure 5 is a horizontal section takenalong the line 5-5 of Figure 4.

Referring to the drawings in more detail, Figure 1 illustrates theapplication of my invention to the cracking of hydrocarbon oils althoughit or receiver I6 equipped with rotary valve II. As shown, this isaccomplished by the use of eductor I8 but in many instances it isnecessary to pump this catalyst into the hydrocarbon stream or to use atall standpipe of catalyst or other means for getting the catalyst intothe vapor stream which is normally at somewhat elevated pressure. Thepressure utilized may merely be sufllcient to overcome the pressuredrops in the apparatus and is normally relatively low, usually not morethan about pounds per square inch.

The particular catalyst utilized does not form any essential part of thepresent invention and a great variety of catalysts are known to the art.Thus, for instance, various natural and acidtreated clays, for instanceacid-treated bentonitic material such as Super Filtrol, can be used anda large variety of .synthetic catalysts such as alumina deposited onsilica, magnesia deposited on silica or the like can be utilized in thecase of catalytic cracking and other catalysts known to the art orhereinafter developed can be utilized in other types of conversionprocesses.

Similarly the size of the catalyst particle can be widely varied,ranging, for instance, from 50 mesh to 400 mesh or even ner, typically200 mesh. As will subsequently be pointed out, the powdered catalyst canhave a rather wide range o particle sizes and this constitutes one ofthe advantages of my invention over prior art methods and apparatus.Thus if the catalyst used is classified as to catalyst size the particlesize in the ninetieth percentile (i. e. the size of those particleswhich are larger than 90% of the particles but smaller than 9% of theparticles) can be three or four or even more times the particle size inthe tenth percentile.

The weight ratio of catalyst to charging stock can be varied withinrather wide ranges, for instance from l to 1 to 5 to 1, typically 2 to1, but the ratio built up within the low velocity zones of the reactorwill be much higher as will hereinafter appear. In special cases higheror lower ratios of catalyst to oil, for example, as low as 1A to 1 andas high as 10 to 1 parts of catalyst per part of oil may be used.

Reverting to Figure 1, the stream of reactant vapors, in this casevaporized hydrocarbon charging stock. carrying suspended powderedcatalyst is introduced through line I9 into an elongated upilow reactor20 of th'e retarded settling type to y which reference has beenhereinbeforemade.

`will be understood readily that similar apparatus and similar processsteps can be applied to other processes as hereinbefore indicated. `InFigure 1 the charging stock which is preferably a virgin gas oil, butwhich can be a. heavy naphtha or other vaporizable hydrocarbon stock, ischarged through line Il to the coils I2 oi furnace I3 and is heatedtothe desired reaction temperature, for instance from about 850 F. toabout 1050u F. The charge is vaporized in furnace I3 and the vaporspassing through transfer line I4 and valve I5 pick up fresh powderedcatalyst from hopper Instead of introducing the vapor and catalysttogther, the catalyst can be introduced directly into the reactor andthe vapor can be introduced into the reactor at a point lower than thepoint at which the catalyst is introduced.

As shown, the vapors and suspended catalyst enter a low velocity zone2l. The charge rate, catalyst size and cross sectional area of thereactor are so proportioned that retarded settling occurs within lowvelocity zones 2l, 22, 23 and 24. In other words, on the average, thecatalyst particles tend to fall downward with reference to the vaporsbut their average rate of slip is less than the vapor velocity so thaton the average the catalyst particles move upwards with reference to thereactor although moving downward with reference to the upflowing vaporstream.

The various variables, notably particle size, charging rate and reactorcross section are pref- 'erably so proportioned that the weight ratio ofcatalyst to vapors within retarded settling zones 2|, 22, 23 and 24 isfrom 50% to 1000% greater, preferably at least greater, than the charge2,4ssfres at various points in the reactor 20 by means of grids 25 whichare provided with uniformly distributed openings 26 and these openingsform high velocity zones interposed between successive low Velocityzones. The velocity within the openings 26 in grids 25, i. e. within thehigh velocity zones, are such that the catalyst particles pass almostwholly upwards and only a little of the coarsest material passesdownward through these grids. Thus the vapor velocity in the highvelocity zones can be equal to the sedimentation rate of some size ofparticles lying somewhere between the i'lftieth and the'ninetiethpercentiles. In fact the grids can advantageously be so designed thatpractically no material passes downward through them. Either effect canbe accomplished by proper proportioning of the total cross sectionalarea of openings 26 in grids 25 to the total internal cross sectionalarea of the reactor 20 so as to give the desired increase in velocitywithin the high velocity zones. (It will be understood, ofcourse, thatmost if not all of the particles, if any, passing downward through thegrids will ultimately pass upward through them once more withoutregrinding and the remainder, if any, can be reground as willhereinafter appear.)

Typically the total cross sectional area of thel openings 26 in one ofgrids 25 should be from 10% to 50%, for instance about 20%, of the totalinternal cross sectional area'of the reactor, the velocity oi the vaporspassing through the openings in the grids being correspondinglyincreased about two to nine times.

er low velocity zone and thus the contact between the vapors and thecatalyst is rendered much more uniform than would otherwise be the case.

`The. use of a large number of relatively small openings is also moreadvantageous than the use of a single opening of restricted crosssection between adjacent low velocity zones since the relatively highvelocity streams enteringr one of the low` velocity zones from the gridimmediately below are absorbed without creating any major turbulence or,in other words, any serious channeling of a type which would interferewith proper contacting. It will be understood. however, that thealternate low and high velocity zones can be of any desired form andthat theuseof grids is merely illustrative.

As shown, the lowermost low velocity zone 2| can be designed^to giveslightly higher average vapor velocities than the upper low velocityzones 22. 23 and 24. One advantageous way of accom-f plishing this is tomake this lowermost low velocity zone of tapered cross section .so thatthe catalyst particles, as previously described, will pass downward tothe bottom of the reactor,

Advantageously these heaviest catalyst particles can pass from thebottom of the reactor into a pulverizer 21 which can be of any desiredtype, for instance, a Raymond type pulverizer, driven by pulley 28 froma source of' power not shown. In this pulverizer the agglomerates orother large and heavy particles are pulverized or repulverized and theycan then be resuspended by continuous or continual introduction of aportion of the charge vapors to the pulverizer by means of valve 29 andline 3|l. Steam or other gas or vapor can be used for this purpose. Alsothe pulverized material' can be introduced into any of the zones orelsewhere in the system alth'ough reintroducing them into lowermost lowvelocity zone 2| is particularly convenient and advantageous.

Thus the heaviest particles passing downward to the pulverizer arecomminuted and then picked up and passed upward into the system oncemore so that they never build up inundesirable quantities and are alwaysavailable for efficient utilization.

From the top of the reactor 20 the stream of vapors and catalyst passthrough transfer line 3| to a suitable separator which can, forinstance, be cyclone separator 32. If desired, two or more of thesecyclone separators can be used in series or other auxiliary m'eans forremoving the last traces of the catalyst can be employed.

The catalyst-free vapors pass out from cyclone separator 32 through line33 to fractionating column 34 equipped with dephlegmating coil 36 andreboiler coil 31 and this fractionator can 'be operated so as towithdraw from the bottom thereof through valved line 38 the materialheavier than gasoline known asA cycle stock, catalytically cracked gasoil or 'middle oil and this can be removed from the system or recycledas a portion of the feed or charging stock.

From the top of fractionator 34 the gasoline and lighter hydrocarbonspass out through line 39 and condenser coil 40 to separator 4 I. Thecondenser coil 40 can beso operated that the liquid withdrawn from thebottom of separator 4| through valved line 42 is predominantly gasolinewhile the lighter gases pass oi from the top of the separator throughvalved line 43. Various more complicated fractionation and stabilizationsystems can and generally will be used as is well known to thosevskilled in the art. -In general I have endeavored kto show my inventionin one of its simplest forms without any attempt to illustrate all theengineering details which are desirable in connection with a commercialinstallation but whichare well within the skill of those familiar withthis art.

From the bottom of cyclone separator 32 the spent powdered catalyst iswithdrawn through rotary valve 44. If desired a portion of this can berecycled directly tothe reactor but all or part of it must beregenerated. This regeneration is usually accomplished by oxidation withair, a mixture of flue gas and air, or some other oxidizing gas in orderto remove carbonaceousimpurities. It can be advantageously regeneratedor reviviiied using apparatus similar to reactor 20; in other words,apparatus with successive high velocity and low velocity zones.

In the form shown, the powdered catalyst passes through line 45 toeductor.46 where it is picked up by steam from line 4l and carried intothe revivication apparatus 48. If desired this eductor can beoperatedfby the use of the rerevivication reactor.

viviilcation gas or 'a pump or other catalyst transferring apparatus canbe utilized. However, one of the advantages of my reviviflcationapparatus is its low pressure drops as compared with the systems withsmall tubes heretofore usually contemplated and this greatly simplifiesthe catalyst transfer problem, making -it possible to utilize eductorsin place of more complicated catalyst transfer apparatus, pumps, etc.

In the reviviilcation step the. powdered catalyst is suspended in steamor other fluid entering the reviviiication apparatus, preferably at thebottom of the lowermost of a plurality of low velocity zones 49. Theselow velocity zones B9 and the alternate high velocity zones can beconstructed as in the case of reactor 20 and a bottom pulverizer cansimilarly be used. However, in the preferred form shown the low velocityzones are delimited by pancake coils 50 through which a cooling mediumis circulated as will later be described. The openings between thesepancake coils form the high velocity zones and can suitably have crosssectional areas within the range pointed out in the case of reactor 20.They serve the purpose of grids 25 in reactor 20 as well as providingfor the circulation of cooling medium to keep the exothermicrevivication reaction from increasing the temperature to a point whichwould injure the catalyst. Usually the reviviiication temperature ismaintained within the range from about 900 F. to about 1100 F.

Air or other reviviilcation gas is introduced from line l, header 52 andvalve 53 into a perforate distributing coil 54 located below thelowermost pancake coil 50, thus picking up the powdered catalyst andcarrying it through the lowermost low velocity zone 69 and thencethrough the high velocity zones which constitute the openings within thepancake coils and through the successive low velocity zones i9 to thetop of the Additional air or other revivification gas can advantageouslybe supplied at progressive points in the revivication reactor, forinstance below each or any of the upper pancake coils 50 by means of thecorresponding perforate distributing coils 54 which are under thecontrol of valves 55. Steam or other diluent gas such as iiue gas canlikewise be introduced at any or all of these points through line 56,maniiold 5l, valves 58 and distributing coils 54.

As previously mentioned, the temperature of the revivication can be keptunder control by circulating any desired cooling medium through pancakecoils 50 by means of line 59, header 60 and valves iii. From the pancakecoils the cooling medium passes out through lines 62, header 53, valves66, header 65 and line 66. If so desired, the cooling medium can bepassed through various pancake coils in series rather than in parallel.A preferred cooling medium is molten salts, for instance.

The design of revivification reactor i3 with alternate low and highvelocity zones has the advantages previously outlined in the case ofconversion reactor 2li and in particular has the advantage of providinga revivification reactor of very low pressure drop which greatlysimplifies the problem of introducing the catalyst into this reactor.

Material from the top of revivification reactor 48 passes through line61 to separator 68 which can be a cyclone separator as shown and theregenerated catalyst from the bottom of this separator can be passed viavalved line 69 into powdered catalyst hopper I6. The spent revivica- 8tion or'regeneration gas can be passed out of the cyclone separatorthrough line 10.

The grids of contacter 20 in Figure 1 can be made adjustable, and theopenings between the cooling coils 50 in reviviiication reactor 48 canlikewise be made controllable if desired. One method of control is shownin Figure 2 which illustrates an alternative form of reactor 20a.

in Figure 2 the grids are composed of vanes 'll arranged in uniformlydistributed apertures in plate 12. The position of vanes 1I can beadjusted by rotating control handles 'I3 so as to place them at anydesired angle, thus controlling the size of the openings between thegrids or, in other words, controlling the vapor velocity in the highvelocity zones. Handles 'i3 are attached to shafts 'l which pass throughthreaded bosses l5 and terminate in links i6 which are attached toframes 'Il which actuate varies 'H through pivots An alternative form ofreactor, 20h, is shown in Figure 3. In this form each low velocity zoneis tapered with the large end upward. The result of this is that withineach low velocity zone the vapor velocity decreases progressively as thevapors pass upwardly through the low velocity zone and then increasessuddenly and greatly as the vapors pass through the high velocity zones'comprising the openings between the low velocity sections. Theconnecting passages may be dened by grids or grills 25h which separatethe low velocity zones.

As the vapor velocity decreases upwardly within one of the low velocityzones due to its taper the force suspending the powdered catalystdecreases with the result that the ratio of catalyst to vapors decreasesor, in other words, the average specific gravity of the material presentin the low velocity zone between two grids decreases with increasingelevation within that zone. This makes for improved stability since thelow specic gravity material does not tend to channel downward as issometimes the case when the average specific gravity is uniformthroughout the whole low velocity zone. Thus contacting is improved as a'result of the streamline flow.

It will be noted that the upper portion 'i9 of the walls defining eachlow velocity zone can be made straight rather than tapered if desired.

The advantage of -tapered low velocity zones is still further enhancedif the vapors and catalyst entering the low velocity zone are given awhirling or centrifugal action, thereby improving the degree ofcontacting, lengthening the path of the vapors and catalyst, and givingcontrolled turbulence. .This result can be accomplished, as shown inFigures 4 and 5, by warping grids 25e into varies in such manner as todirect the material passing through these grids tangentially.

One simple way of accomplishingthis, as shown in Figures 4 and 5, is toform these grids or grills :from sheet metal by making radial cuts inthe sheet metal and then raising the metal to a diagonal' position ateach` one of the cuts to form bailies 30 so that the upowing materialsare directed tangentially or spirally or, in other words,

given a horizontal as well as a vertical component thus giving acontrolled swirling motion. As a result of this rotating movement of thevapors and catalyst mixture Iwithin the low velocity zones of thecontactor, a portion of the catalyst is thrown by centrifugal action tothe sides of the low velocity zones where it escapes the principal forceof the vapors and falls back into the vortex of the vapor stream at grid25c. The catalyst is there again picked up and recirculated within thelow velocity contacting stage 19c. In this manner the catalyst isexposedto the action of the hydrocarbon vapors for a considerably longerperiod of time than would be the case were it allowed to travel directlythrough the contacting zone without rotational eifect.

While I have described my invention in connection with certain specificembodiments thereof, it is to be understood that these are by way ofillustration rather than by way of limitation and that I do not mean tobe restricted thereto but only to the scope of the appended claims.

I claim:

1. In a catalytic conversion system wherein powdered catalyst issuspended in charging stock vapors, passedthrough an up-flow reactor,separated from reaction vapors, suspended in regeneration gas, passedthrough an up-iiowv regeneration chamber, separated from regenerationgas and reintroduced into further amounts of charging stock vapors andwherein the catalyst particles tend to agglomerato during continued useof the system, the method'of operation which comprises regulating thevertical gas or vapor velocity in one of said up-ilow chambers to permitagglomerated catalyst particles to settle to thel base of said up-flowchamber while maintaining the unagglomerated particles in suspension,withdrawing the agglomerated particles from the base of said up-ilowchamber` pulverizing said withdrawn particles and reintroducing saidpulverized catalyst into the system.

2. An apparatus for contacting gases or vapors with a suspended powderedsolid which comprises an upow contacting chamber of increasing diameterfrom the bottom thereof to a point adjacent the top thereof, means forintroducing powdered solids suspended in gases or vapors at the bottomof said chamber, an outlet of relatively small cross-sectional area atthe top of said chamber, a second uplow contacting chamber of increasingdiameter from the bottom thereof to a point adjacent the top thereof,the bottom of said secondvchamber communicating with the smallcross-sectional area outlet of the first chamber, a discharge' means ofrelatively small cross-sectional area leading from the upper part ofsaid second contacting chamber and means at the base of said secondcontacting chamber for directing. vthe upflowing stream tangentiallythereto.

catalyst and vapors from a preceding to a succeeding zone, means forseparating catalyst from reaction vapors, a second substantiallyvertical conduit depending from said catalyst separating means, a secondupilow contacting chamber, means for suspending catalyst in a gaseousstream at the base of said second conduit and for introducing saidsuspended catalyst at a low point in said second upiiow contactingchamber, means for abstracting heat from catalyst in said secondcontacting chamber and means for separating catalyst from gases leavingsaid second contacting chamber and for returning said separated cata.-lyst to said first catalyst receiver.

4. An apparatus for eecting catalytic conversion of hydrocarbons bymeans of a powdered catalyst which apparatus comprises a powderedcatalyst receiver, a substantially vertical conduit -depending from saidreceiver and communicating therewith, means for vaporizing a hydrocarboncharging stock, a vapor transfer line leading from said vaporizing meansto and from the base of said conduit and so constructed and arrangedthat catalyst from said conduit may be suspended in charging stockvapors in said transfer line and conveyed thereby to a low point in arst vertical upow contacting chamber, a ilrst vertical upilow contactingchamber of sicient diameter to permit a ratio of'catalyst to chargingstock vapors thereinvwhich is higher than the ratio of catalyst tocharging stock vapors inthe transfer line,

means for separatingVv catalyst` from reaction V vapors, a substantiallyvertical conduit depending sion of hydrocarbons by means of a powderedcatalyst which apparatus comprises a powdered catalyst receiver, asubstantially vertical conduit depending from said receiver andcommunicating therewith, means for vaporizing a hydrocarbon chargingstock, a vapor transfer line leading from said vaporizing means to andfrom the base of said conduit and so constructed and arranged thatcatalyst from said conduit may be suspended in charging stock vapors insaid transfer line and conveyed thereby to a low point in a firstvertical upflow contacting chamber, a iirst vertical upflow contactingchamber of sufcient diameter to permit a ratio of catalyst to chargingstock vaporsr therein which is higher than the ratio of catalyst tocharging stock vapors in the transfer line, said chamber beingconstructed and arranged to receive charging stock vapors and powderedcatalyst from said transfer line, means, in said first vertical upowcontacting chamber for dividing said chamber into.a plurality ofseparate contacting zones and for tangentialiy distributing from saidcatalyst separating means, a second vertical upilow contacting chamber,means for abstracting heat from catalyst comprising a substantiallyhorizontal heat exchanger within the second contacting chamber itself,said means being constructed and arranged for subdividing said second'vertical upilow contacting chamber into a plurality of separatecontacting zones and for distributing catalyst from the zone on one sideof said distributing means to the zone on the other side thereof, meansfor suspending catalyst in a gaseous stream at the base of said secondconduit and for introducing said suspended catalyst at a low point insaid second vertical upilow contacting chamber, and meansior separatingcatalyst from gases leaving said second contacting chamber and forreturning said separated catalyst to said first catalyst receiver.

VANDERVEER vooRHEEs.

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